"PDQ Epidemiology" will help to fill the considerable gap between the exact findings of the laboratory and the uncertain world of clinical medicine. By translating the terminology of epidemiology into easy-to-understand language, the underlying scientific methods begin to emerge and make sense. The third edition reflects the maturation of the field, which now encompasses much more than the 'randomized, controlled trial.' New sections explain techniques that have been introduced into the field since the previous edition, the section on RCT has been expanded and updated examples have been incorporated. The section on measurement has also been brought into line with newer thinking on reliability and validity. Featuring unique examples titled Circular Reasoning and Anti-intellectual Pomposity Detectors (CRAP Detectors), the text helps the reader identify studies with basic flaws in design or reasoning.